The purpose of this Core is to efficiently provide purified mouse islets to investigators participating in this Program Project. Projects 2 and 2 will utilize mouse pancreatic islets in the performance of the proposed research. To provide this service, the production of mouse islets will be centralized into a single facility and available to the investigators of this program. The personal in this core will also assist in transplantation of engineered islets under the renal capsule of transplant-recipient mice. The Core will be directed by Dr. Norman Fleischer. Prioritization of its activity will be by consent of the participants of the program.